Assig-noe to



P. BRADFORD. Flush-Bolt.

Patented Feb; 17,

UNITED STATES PATENT OFFICE.-

PURMORT BRADFORD, OF NEW HAVEN, CONNECTICUT, ASSIGNOR TO SARGENT & 00.,OF SAME PLACE.

FLUSH-BOLT.

SPECIFICATION forming part of Letters Patent No. 224,638, dated February17, 1880. I

Application filed December 26, 1879.

.and State of Connecticut, have invented a new Improvement inFlush-Bolts; and I do hereby declare the following, when taken inconnection with the accompanying drawings and the letters of referencemarked thereon, to be a full clear, and exact description of the same,and which said drawings constitute part of this specification, andrepresent, in-- Figure 1, front view; Fig. 2, side view; Fig. 3, rearView. I

This invention relates to an improvementin that class of bolts commonlytermed flushbolts, such as are commonly used at the top and bottom ofone of a pair of doors. These are usually constructed with somefrictional device to hold them in their drawn position, or in some caseswith alatching device, which will hold the bolt in one direction, and aspring to hold it in the other; but in none is there that positivesecurityfor the bolt in both the drawn and thrown positions which isdesirable in this class of bolts. To produce this result is the objectof this invention; and it consists in the construction, as hereinafterdescribed, and particularly recited in the claim.

A is the plate or body of the bolt; B, the bolt-head, which extendsthrough the rightangular end 0 of the plate A, and from which aconnecting-rod, cl, extends to the bolt-spindle D, as seen in Figs. 2and 3. The two sides of the cam a are made straight, and onto each ofthese two sides one arm, 0, of a doubled spring rests, as seen in Fig.3, grooves being formedin the sides of the cam to prevent the springslipping off. The two arms 6 extend from a coil, f, which is held fastto the plate.

When the bolt is thrown the crankpin is at its lowest point below theaxis of the knob or cam a, and as seen in Fig. 3. Now ifthe knob beturned it Will turn the cam, the springs c 6 will spread, and the boltwill be moved until the crank-pin b beat a point in the same line, butabove the axis of the cam. as seen in broken lines. In coming to thislatter position the springs close upon the sides of the cam, but uponopposite sides to their first po sition. This enables the spring to holdthe cam in, and also tends to throw it toeither of its extremepositions, so as to secure the bolt in either of its two positions,which positions are in vertical or longitudinal line of the bolt throughthe axis of the cam.

While a two-armed spring is the best, because each arm forms a supportor resistance for the other, a spring with a single arm may be appliedin the same manner.

I claim The combination of the plate A, the bolt and its spindlearranged thereon, with an external knob connected to and so as torevolve the cam upon the inside, the said cam connected to the bolt by acrank-connection, and a spring bearing upon said cam, so as to hold thesaid cam and bolt in either of the extreme positions, substantially asdescribed.

\ PURMORT BRADFORD.

Witnesses:

GEO. M. VAN DEWATER, WM. S. COOKE.

